This project seeks to elucidate the mechanisms by which oral perceptual experience is generated. Since objective measurement of the various aspects of oral experience is fundamental to this effort, the selection and refinement of appropriate psychophysical methods is a primary and continuing project concern. Currently, the routine assessment of taste is carried out using aqueous solutions representing each of the four basic tastes. Measures include both (detection) thresholds and judgments of intensity for taste stimuli at higher, more commonly encountered levels of strength. Olfactory function is routinely assessed by a standardized test of odor identification. Assessments of sensitivity to local pressure on the tongue and to variation in the temperature or the viscosity, of an oral bolus are also available. These methods, applied to the study of oral perceptual changes may occur with oral or systemic disease and its treatment, with salivary gland dysfunction, with aging or as an isolated complaint can provide insights into basic mechanisms of normal chemosensory perception. Direct investigations or oral sensory mechanisms in individuals lacking oral complaints or disfunction can also advance the understanding of the mechanisms by which the complex oral stimuli encountered in everyday life are perceived.